Oxygen vacancies are increasingly recognized to play a role in phenomena observed at transition-metal oxide interfaces. Here we report a study of SrRuO3/La0.7Sr0.3MnO3 (SRO/LSMO) interfaces using a combination of quantitative aberration-corrected scanning transmission electron microscopy, electron energy loss spectroscopy, and density-functional calculations. Cation displacements are observed at the interface, indicative of a dipole-like electric field even though both materials are nominally metallic. The observed displacements are reproduced by theory if O vacancies are present in the near-interface LSMO layers. The results suggest that atomic-scale structural mapping can serve as a quantitative indicator of the presence of O vacancies at interfaces.
@article{arxiv.1111.0023,
title = {Direct Observation of an Interface Dipole between Two Metallic Oxides Caused by Localized Oxygen Vacancies},
author = {A. Y. Borisevich and A. R. Lupini and J. He and E. A. Eliseev and A. N. Morozovska and G. S. Svechnikov and P. Yu and Y. H. Chu and R. Ramesh and S. T. Pantelides and S. V. Kalinin and S. J. Pennycook},
journal= {arXiv preprint arXiv:1111.0023},
year = {2012}
}